Paraffin scraper



July 17, 1962 M. L. CLAIBORNE PARAFFIN SCRAPER Filed Aug. 25, 1959RSI-IALL L. CLAlBORNE INVENTOR.

- 3,044,552 PARAFFIN SCRAPER Marshall L. Claiborne, 206i W. Alto, Hobbs,N.V Mex. Filed Aug. 25, 1959, Ser. No. 835576 3 Claims. (Cl. 16d-170)This invention pertains to oil Wells and more particularly to a devicefor scraping para'in from the inside or" the production tube of a freeowing oil well.

This device is particularly designed and adapted to be used upon oilwells which have sufficient pressure to cause the oil to flow freelythrough a tube to the surface of the ground. A common problem with suchtype oil wells is the collection and accumuiation of paraffin on theinside of the tubing.

This tool operates on the principle that the liow of the well may bestopped by closing a valve at the top of the well. Therefore any objectin the Ytube which is heavier than the liquid in the tube will fall. Onthe other hand, if the valve at the top of the well is open, any objectin the well will be carried upward with the iow of oil in the well.

An object of this invention -is to provide such a free fall device whichwill effectively scrape the paratiin from the inside of the tube.

Another object is to provide such a tool which has little or nodificulty in freely falling when there is no ow of oil in the well yetwhich has good scraping action on both the downward and upward trip.

A further object of this invention is to provide a tool which is easy tocatch and hold within the lubricator -at the upper portion of the tube.

Still further objects are to achieve the above with a device that issturdy, compact, durable, simple, and reliable, yet inexpensive and easyto manufacture.

The specific nature of the invention as Well as other objects, uses, andadvantages thereof will clearly appear from the following descriptionand from the accompanying drawing, in which:

FIG. 1 is an elevational view of said tool in the tube.

FIG. 2 is a partial longitudinal section of the joint between the upperand lower section of the tool.

FIG. 3 `is a partial longitudinal section of the joint between the lowersection of the tool and the stop member.

As may be seen in the accompanying drawing, the tool is basicallydivided in two sections. As this general type of tool is well known, thelubricator and the catch in the bottom have not been shown.

The upper section of the tool is basically a cylindr-ical body or member12 which is closed at the top end. The top end is closed by shaft 14 forthe easy engagement of fishing tools, generally called a fishing neck.

Around the exterior of the body 12 are two helical vanes 16. These vanesare welded or otherwise iirmly secured to the body. The outside diameterof the tool with the vanes is only slightly smaller than the insidediameter of the tube within which the tool works.

Likewise lower section 18 has body 20 which is of cylindrical form. Thebody has two vanes 22 helically around it. As may be seen, both thebodies of the upper and lower section are made of tubular material. Thetop of the lower section body 20 has a plug 24. The outside diameter ofthe plug is the same as the inside diameter of the body so thereds asnug iit. Holes may be bored in the side of the body 20 so that theplugis welded in place through the holes to the body 20. Pintle 26 risescoaxially with the tubular body 20. It is an integral part of the plug24. The pintle extends through hole 23 of Washer 30 which is 4at-tachedto the lower end of the tubular upper body 12. Holes may be boredthrough the upper body 12 to weld the washer 30 in place. As may beseen, the washer has a substantial 3,4%,552 Patented July l?, 1962thickness. The hole 28 is larger than the outside diameter of the pintle26. Therefore there is a certain amount of play or possibility ofvibration between the upper body and the lower body. A protuberance orstop or nut 32 is screwed onto threads at the top of the pintle andwelded into place at the top of the pintle which is above the washer. Asstated before, the whole connection is sornewhat rough and permittingand encouraging Vibration for reason which will be explained later.

Stop 34 is below vthe bottom section. The outside diameter of the stopis larger than the outside diameter of the tubular body 20 which is ofthe same diameter as the tubular body 12. However the diameter of thestop is less than the outside diameter of the entire tool includingvanes. Likewise extending vertically upward from the stop and coaxialwith the tubular members s pintle 36 which extends through washer 38which is attached to the lower body in the same manner as Washer 3G isattached to the upper body. Likewise a nut or not to hang easily becauseeach of the sections will tend to spiral as it goes down. 'If the toolhits some obstruction in the tube, the parts will spiral around as theygo down. However, because the swivel between the lower member and theupper member is not machined to perfection, there will be a certainamount of friction and vibration. This prevents perfect spiraling and`accomplishes a great deal of paraffin removal. If only a single memberis used which has a spiral in only one direction, it will tend to make ahelical track down the inside of the tube and following this same trackon repeated trips. If right and left handed veins are used on a singlemember with no possible rotation between the two sections, there is nospiraling at all when the tool is traveling and more likely the toolwill become stuck on paraiiin deposits as it falls.

I have found it desirable to add a stop on the bottom which is mountedfor rotation. When the tool'strikes the catch which is mounted in thetube at the lower extreme of the tools travel, there is no excessiverotation against the catch. Likewise when the tool is blown upward andthe tool is caught in the lubricator at the top of the tube, the stopcan rest without having a friction drag on the catch even if 4the bottomsection is still rotating due to the passage of uid by it.

Specifically I have found that following dimensions give good resultsfora tool adapted to work within a 2 inch LD. tube. The bodies 12 and 20are made from 1/2 inch steel pipe (.840 inch O.D.) each about 81/2inches long. The vanes 16 and 22 each make one complete revolutionaround the body and are constructed from 12 guage steel welded to thebody. The entire tool is 20 inches long and weighs three pounds. Thediameter of across the vanes is 1% inches and the diameter of the stopis 15/8 inches.

tI-t will be apparent that the embodiment shown is only exemplary andthat various modifications can be made in construction, materials, andarrangements within the scope of the invention as defined in theappended claims.

and the vanes on the bottom portion rotating in a second direction, apintle attached to one of said portions, a washer attached to the otherof said portions, said pintle extending through said washer and having astop at the l end ofthe pintle which is beyond said washer, so that thetwo membersv are connected together for relative rotation but with onlyslight axial movement. A

2. The invention as dened in claim'l with the addition of a disc shapedstop upon the bottom of the bottom portion co-axial therewith, said stopbeing of lesser diameter than the outside diameter of said vanes but ofgreater diameter than the diameter of the portion to which the variesare attached, said stop having a pintle extending upward from the topthereof, said bottom portion having a washer in its bottom, said stoppntle extending through said bottom washer, a protuberance upon the topof the pintle Which is above the Washer, thus mounting the stop forrelative rotation to the bottom portion but little axial movementrelative to the bottom portion. Y Y

3. A paralin scraper for oil Wells comprising: an upper cylindricalmember with helical vanes on the exterior thereof, said helical vanesrotated around the outside of the member in a first direction; a lowersecond cylinfdrical member with helicalvanes on the outside thereof, thevanes of the second member rotated around the outside of the secondmember in a second direction; said cylindrical members being arrangedcoaxially vertically within a tubular member of said oil Well, meansconnecting said `first and second members for Vfree rotation in allpositions relative to each other, but for only slight axial movementwith respect to each other; anda stop on the bottom oi the lower of thetwo members, said stop having a smooth exterior surface, and said stopbeing mounted for free rotation relative to the lower of the twomembers.

References Cited in the tile of this patent UNITED STATES PATENTS1,372,904 Regenier Mar. 29', 1921 1,810,260 Swinford f I une 16, 1931r2,201,680 Haynes May 21, 1940 2,326,528 Festervan et al. Aug. 10,. 19432,636,565 Williams Apr.l28, 1953 2,679,905 Mangum et al. June 1, 1954

